Deflectometer.



W. FENTZLOFI'.

DEPLEGTOMETBR.'

APY'LIOATIoN FILED nu 25,-1909.

1,015,305. Patented Jan. 23, 1912.

WITNESS/58 lfH/ENTOH ATTORNEYS oivinin srA'rEs nnrnncroivin'riin.

To all whom it may concern: Y* y Be it known that I, ILHELivrFnNTZLorF,

subject of the German Emperor, residingatl 25 Schneckenhofstrasse, Frankfort-on-the- Main, in the lampire of Germany, manufacturer, have invented certain new and useful Improvements in Deflectometers, of which the following is a specification. v f

apparatus for measuring linearyniovements by means of a' member passing between a friction roller carrying the Vpointer or -'in'- deX and a pressure piece.

The invention has for its objectjto cor?. rect the insufficient exactness of the ordify nary apparatus of this lkind, so that the slightest defiections and linear movements can be read off with the greatest eXactness rapidly and with certainty. I

An example of construction lof lthe inven` tion is represented in the accompanying drawings, in which Figure 1 is a front view with the scale partly broken away; Fig. 2, a plan view;y and Fig. a partial section; Fig. 4:' shows an example of how the apparatus can be ap-` plied. e

The apparatus consists of ahollow rec-1 tangular frame a with a semi-circular scaley ment and is in the form of a wire, band,;or the like, can be passed .between the friction and the pressure rollers. For the same ob-i ject the rear wall of Vthe frame a has a slot lo at the place in question. The pressure roller` f is guided in a straight Yline in order to cause it to approach the friction` roller d in an exactly lineardirection, so that a uniform pressure is exerted on the transmitting member and causesa uniferinmovement of the friction roller. The counterbalancedj pointer o acts on the slightest-movement of the friction roller ci and remains stationary in any position.

This invention relates toan improvemen f in the so-called deflectometers,that is to say This isv counterbalanced andI` The pressure piece consistsof 'ieoeflyseriai no. 498,335. e,

The apparatus described isespecially-in.-

tended'for measuring deiiections, more par-y ticularly elasti'cvdeflections of iron and 'concrete constructions Ain buildingllofty struc- Spec'icatironiof `Letters Patent. y

3.111,23, v Application filed May a5, l

tures and bridges. It may for this purpose be erectedr in various ways andeacts equally lreliably in' any position. One method 0f erection is shown as an example in Fig.vv

In this,.1 indicates a tubular pillar "or up- A"right adapted to be driven into the ground, having an attachmentplate Zadapted to be secured or firmly clamped at a' suitable` height, to 4which n, plate the apparatus is w l. For the purpose of more convenientlyiii;-k ying Jup. the' apparatus, transverse 'slots are screwed.

provided in the` frame of tlie'apparatus` and yloiig-itgudinal slots in the'fastening Yplate for f the screws. The upper end of the transmitting membeigf in the form ofa band 3, is connected with the object which makes the 'movement to-.be measured. For. the purpose -of drawing the v transmitting member taut,y itsffree-end is loaded with a weight 4."

.In order to introduce vthe transmitting member between the' friction and the pres,- sure rollers, lthe latterl is moved somewhat back by means of the slide h, and the transmitting member insertedV .between ther two e rollers. The `pressure roller is'then allowed tospring'back again, and it then presses the transmitting vmember 'against the Vfriction*l roller.,V If the transmittingmember makesa linear movement, the friction roller d is correspondingly rotated,v and the' extent of this movement is indicated by the/movementy of thefpointer c on the scale b.

y In consequence ofthe counterbalancingf ofthe pointer, the mounting of the friction' rolleron.r points and the linear'pressurepf thepressing roller, the greatest possible exi] actness in the measurement is obtained.

I declare that whatlclaim is :-v f

a scale, a ybalanced.fpfointer, a roller carryf .ing said pointer, bearings Vfor said roller, xwhich'coniine it to rotary movement; a pressure roller in contact with the roller which carries the pointer; a slide carrying said y pressure roller, a spring crowding saidpresfVA sure roller against the roller which carries'I the pointer, and a slotted frame carrying said slideyand a handle formoving said slide, substantially as described.

1..In a deflectometer the'co'mbination yof iio said pointer, bearings for said roller, Which ing said slide, and a handle for moving said conne it to rotary movement; means for slide, substantially as described. 10 adjusting the tension of said bearings; a In Witness whereof I' have hereunto set pressure roller in Contact With the roller my hand in presence of two Witnesses.

which carries the pointer; a slide carrying WILHELM FENTZLOFF. saidpressure roller; a spring crowding said Witnesses z' pressure roller against the roller Which oar- JEAN GRUND,

ries the pointer, and a slotted frame oarry- CARL GRUND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

